In the manufacture of contact lenses by the so-called full-mold process (casting process), contact lenses are usually produced by dispensing a specific amount of a polymerizable contact lens material into the female mold half. The mold is then closed by putting on the male mold half, a molding cavity being enclosed between the two molding surfaces. In that molding cavity there is the previously dispensed contact lens material, which is polymerized to form an as yet unhydrated contact lens. Subsequently, the mold is opened and the polymerized but as yet unhydrated contact lens is removed and further processed.
Unfortunately, it is not possible as a rule to predict reliably to which of the two mold halves the contact lens will adhere: in some cases it adheres to the male mold half (mold half with the convex molding surface) and, in others, it stays in the female mold half (mold half with the concave molding surface). After opening of the mold, therefore, a check must be made in every case to discover on or in which mold half the polymerized but as yet unhydrated contact lens is located.
Therefore, there is a need to provide a process for casting—molding contact lenses with enhanced quality and enhanced yield achieved by omitting the previously required check to discover on or in which mold half the contact lens is located after the mold has been opened. Therefore, the process can nevertheless proceed automatically since it can reliably be assumed that the contact lens will adhere to one of the two mold halves. The process can also be simplified to need to optimize only for one mold half.